Rare presentation of the cutaneous metastasis of colon cancer imitating herpes zoster

The cutaneous metastasis of colon cancer is rare, and most commonly manifests as nodules or masses. In the case of our patient, a rarely described vesiculomaculopapular rash resembling herpes zoster was observed and treated as such; however, biopsy later revealed metastatic colonic adenocarcinoma. Metastasis of colon cancer to the skin typically confers a poor prognosis, however, early identification may allow for quicker intervention and more aggressive treatments, that may extend survival. Given the immunocompromised state of cancer patients undergoing antineoplastic therapy, a herpes zoster eruption would not be unexpected, but an astute primary care provider should keep metastatic disease in their differential.